The influence of use additives on nitrous oxide emission during swine slurry composting.

use of additives (Mg/P and nitrification inhibitor dicyandiamide - DCD), on nitrous oxide emission during swine slurry composting. The experiment was run in duplicate; the gas was monitored for 30 days in different treatments (control, DCD, Mg/P and DCD + Mg/P). Nitrous oxide emissions rate (mg of N2O-N.day-1) and the accumulated emissions were calculated to compare the treatments. Results has shown that emissions of N-N2O were reduced by approximately 70, 46 and 96% through the additions of DCD, MgCl2.6H2O + H3PO4 and both additives, respectively, compared to the control. Keywords Composting; swine slurry; additives; nitrous

Dedifferentiation of Leaf Cells and Growth Pattern of Calluses of Capsicum annuumcv. Etna.

Background:In vitrocell suspension cultivation systems have been largely reported assafe and standardized methods for production of secondary metabolites with medicinaland agricultural interest.Capsicum annuumis one of the most widely grown vegetablein the world and its biological activities have been demonstrated against insects, fungi,bacteria and other groups of organisms. The determination of procedures for thededifferentiation of cells into callus cells and the subsequent study of the callus growthpattern are necessary for the establishment of cellsuspensions and also to subsidizestudies regarding the bioactivity of its secondarymetabolites. To date, no study hasdescribed the development of protocols for callus induction inC. annuumL. cv. Etna. Objective:The objective of this study was to establish a protocol for dedifferentiationof leaf cells of the cultivarC. annuumcv. Etna and to determine the growth pattern ofthe calluses with a focus on the deceleration phase, when the callus cells must besubcultured into a liquid medium in order to establish cell suspension cultivationsaiming at the production of secondary metabolites.Results:The treatment that resultedin the highest %CI, ACCC and callus weight was thecombination of 4.52 μ M 2,4-D +0.44 μ M BA. The calluses produced were friable andwhitish and their growth patternfollowed a sigmoid shape. The deceleration phase started on the 23rdday of cultivation.Conclusion:Callus induction in leaf explants ofC. annuumcv. Etnacan be achieved inMS medium supplemented with 4.52 μ M 2,4-D + 0.44 μ MBA, which results in highcellular proliferation; in order to start a cell suspension culture, callus cells on the 23rdday of culture should be used.

Geographic pattern of genetic diversity in natural populations of rosewood (Aniba rosaeodora), in the Central Amazonia.

Padrão geográfico de diversidade genética em populações naturais de Pau-rosa (Aniba rosaeodora), na Amazônia Central.

Typologies and spatialization of agricultural production systems in Rondônia, Brazil: linking land use, socioeconomics and territorial configuration.

The current Amazon landscape consists of heterogeneous mosaics formed by interactions between the original forest and productive activities. Recognizing and quantifying the characteristics of these landscapes is essential for understanding agricultural production chains, assessing the impact of policies, and in planning future actions. Our main objective was to construct the regionalization of agricultural production for Rondônia State (Brazilian Amazon) at the municipal level. We adopted a decision tree approach, using land use maps derived from remote sensing data (PRODES and TerraClass) combined with socioeconomic data. The decision trees allowed us to allocate municipalities to one of five agricultural production systems: (i) coexistence of livestock production and intensive agriculture; (ii) semi-intensive beef and milk production; (iii) semi-intensive beef production; (iv) intensive beef and milk production, and; (v) intensive beef production. These production systems are, respectively, linked to mechanized agriculture (i), traditional cattle farming with low management, with (ii) or without (iii) a significant presence of dairy farming, and to more intensive livestock farming with (iv) or without (v) a significant presence of dairy farming. The municipalities and associated production systems were then characterized using a wide variety of quantitative metrics grouped into four dimensions: (i) agricultural production; (ii) economics; (iii) territorial configuration, and; (iv) social characteristics. We found that production systems linked to mechanized agriculture predominate in the south of the state, while intensive farming is mainly found in the center of the state. Semi-intensive livestock farming is mainly located close to the southwest frontier and in the north of the state, where human occupation of the territory is not fully consolidated. This distributional pattern reflects the origins of the agricultural production system of Rondônia. Moreover, the characterization of the production systems provides insights into the pattern of occupation of the Amazon and the socioeconomic consequences of continuing agricultural expansion.